[email protected] hath wroth:
Can anyone tell me any experience of how and when slip rings will
catch fire?
Any respond appreciated!
Slip rings are made from copper alloy. Copper does not burn. The
brushes are made from everything from conductive materials to powdered
carbon and/or metalized graphite mixtures, which will burn quite
nicely. If your brushes are on fire, you are probably drawing too
much current, which is usually what happens when your rotor field
windings develop a shorted turn or you overload your unspecified
motorized contrivance. Slip rings are also used only in AC
alternators, where a shorted diode can cause excessive current. You
can also create a fire by using the wrong material for replacement
brushes, the wrong size brushes, or insufficient contact area (high
current density). If this happens to be an ST generator head you're
trying to repair, the following might be useful:
<
http://www.utterpower.com/ST.htm>
Notice that on 5kw and up models, dual brushes are used on the slip
rings.
